Fire arch for furnaces



Jan. 4, 1927 1,612,795

L. s. ABBOTT FIRE ARCH FOR FURNACES Filed Dec. 21, 1925 3 Sheets-Sheet 1 Inventor Lyle Stockton AbboIT Affomey Jan. 4, 1927. s. ABBOTT FIRE ARCH FOR FURNACES Filed Dec. 21, 1925 3 Sheets-Sheet 2 W maxim 23/ 2 Wu/WW [me flag] dge/7140 Attorney Jame 4,1927,

L. S. ABBOTT FIRE ARCH FOR FURNACES Filed Dec. 21, 1925 13 Sheets-Sheet 3 Inventor Patented Jan. 4, 1927.

LYLE STOCKTON ABBOTT,

OF CHICAGO, ILLINOIS, ASSIGNOR T CHICAGO FIRE BRICK COMPANY, A CORPORATION OF ILLINOIS.

FIRE ARCH FOR FURNACES.

Application filed December 21, 1925.

My invention relates to fire arches for furnaces and more particularly to a new and improved hanger and refractory struction for such arches. 6 My invention relates to arches composed of refractory material such as refractory bricks or blocks forming the roofs of furnaces which are generally known as suspended arches. More particularly my inventlon relates to such arches in which the bricks or blocks are suspended from an overhea framework which is protected from the heat of the furnace.

One of the purposes of my invention is to provide an arch of the above mentioned character in which any portion thereof can be replaced or repaired without disturbing any other portion. In order to accomplish this the arches are made up of units COIHPIIS- ing a hanger and refractory blocks supported thereby, said hanger and the blocks there on being removable without disturbing the other hangers or blocks or bricks carried thereby.

It is another purpose of my invent on to provide means for combining a plurahty of small bricks or blocks into units which are independently or individuall suspended from the overhead framewor in such a manner that a high degree of flexibility is obtained to thus limit the tendency for spalling or chipping of the bricks due to fricton and pressure of the bricks or blocks against each other which would occur due to temperature changes if no such flexibility were. provided.

. It is a further object ofthe invention to provide a fire'arch construction for furnaces that is economical to install and which can be readily and cheaply repaired.

It is still a further purpose of the invention to provide bricks or blocks-for use in a suspended arch that are so constructed that they will be free from cracks due to the drying and firing of said bricks or blocks and free from internal strains which weaken such refractory members as have been used prior to my invention. This is accomplished by avoiding any re-entrant angle in the outline of the brick or block and by providing, instead of the usual groove that is undercut for receiving the hangers, an opening extending through from one face to the opposite face of said brick or block that has an uninterrupted wall portion and which is adapted to receive means on the hangers.

block conclay tiles true to shape and Serial No. 76,775.

It is another purpose of the invention to provide hangers for suspending the bricks or blocks which will have no tendency to disrupt or damage said bricks or blocks while in service, and to provide means for detachably mounting said bricks or blocks thereon, said hangers being provided with means to prevent the disengagement of said bricks or blocks from said hangers.

Obviously an arch of the above mentioned character could be made of small bricks with separate individual hangers, but this would not only be very expensive, but the hangers and. carrying members therefor would be so close together that it would be extremely dif ficult, if not impossible, to repair the arch due to inaccessibility of its parts. On the other hand, if the hangers and carrying members therefor are spaced far enough apart for accessibility and convenience, tiles of large size are required. It is not only expensive, but diflicult to make large fire size due to the character of the material and the methods that must be used in manufacturing the tiles or, blocks. en tiles or blocks of large size are used in the construction ofthe suspended arch, these lrregularities and variations in size create open joints or interstices between the tiles. The flames in the furnace enter into these openings causing the tiles or blocks to heat up on the sides as well as on the bottom face, resulting in abnormal exansion of the lower portion of the tile or lock. This localized expansion is the prin-. cipal cause of spalling which 'causes rapid destruction of the title with resultant overheating of the metal suspension and resultant damage and consequent failure thereof.

By my arrangement and construction of 95 hangers, I am enabled to make my refractory material in the form of small bricks or blocks arranged in units supported by a single hanger. This permits wide spacing of the hangers and carrying members and makes'the elements of the arch more readily accessible for purposes of installation and repair. By making said bricks or blocks of a shape so as to avoid all reentrant angles and of small size, the same can be made very 105 closely to dimensions, practically free from distortion and warpage and free from cracks due to the drying and firing thereof. As a result, the bricks or blocks fit more closely together, avoid all open joints of such a size as would admitfiame or heat action, and the life of the same is greatly increased. ThlS is due to the fact that instead of there being a tendency of the bricks to spall, the flame action tends to glaze the undersurface of the arch sealing the joints and preventing air infiltration. The close fitting of the bricks or blocks is obtained by providing an offset inwardly in the one face thereof whereby the portions of the hangers that must extend between the bricks or blocks will be accommodated between the reduced portions thereof, formed, due to such oflsets. The like of the bricks or blocks is furthermore increased due to the fact that the same are provided each with a single opening therethrough from the offset face to the opposite face, the walls of said openings having no breaks therein. This prevents the formation of cracks in the drying and firing of the refractory blocks or bricks which would otherwise cause portions thereof to break off and which in the case of grooved blocks would cause the same to be dislodged from the hangers when the fracture occurs.

Other objects and advantages of the invention will appear as the description of the accompanying drawings proceeds. However, I desire to have it distinctly understood that I do not intend to limit myself to the exact details shown or described, but that I intend to include as part of my invention all such obvious changes and modifications of parts as would occur to a person skilled in this art and as would fall within the scope of the claims.

In the drawings:

Fig. 1 is a plan view partly broken away of an arch constructed in accordance with my inventlon;

Fig. 2 is a section thereof taken on the line 22 of Fig. 1;

Fig. 3 is a top plan view of one of the assembledunits of my arch;

F g. 4: is a vertical sectional view thereof;

F g. 5 is an end view of said unit;

Fig. 6 is a perspective view of one of the bricks or blocks used in the arch; and

Fig. 7 is a perspective view of one of the anger bars used for supporting the bricks or blocks in the arch.

Referring in detail to the drawings, the arch is shown as being supported upon a plurality of bars 10 which may be in the form of angles and which are supported by means of the walls 11 of the furnace and upon the centrally extending beam 12 which is shown as being an I beam. The hangers for supporting the refactory bricks or blocks comprise the hook members 13 which have books 14 thereon engaging the angles 10 and hooks 15 that are adapted to engage in the apertured ears 16 in the hanger bars 17, one of which is shown in perspective in Fig. 7.

Said bars 17 are curved on their upper surfaces as indicated at 18 with a strengthening web 19 on the under side thereof and with enlargements 20 at the ends thereof that serve as stop projections or flanges. I

Mounted on said members 17 are the blocks or bricks of refractory material 21. One of said blocks is shown in perspective in Fig. 7. tangular in formexcept for the offset portion 22 in the one face 23 thereof. The opposite face 24 is substantially plane. The corners are substantially right angular except at the bevelled portions '25, and the in- Wardly offset portion 22 joins with the face 23 by means of the curved portion 26. The substantially circular opening 27 extends from the inwardly offset portion 22 of the one face to the opposite face 24, and the wall portion of said hole or opening 27 is unbroken from end to end thereof. As will be evident from Figs. 2 and 4, the bricks or blocks 21 are mounted in position on the members 17 by movement of the same endwise along the member 17 from the ends 20 thereof toward the centrally apertured ear 16 thereof. The upper curved face 18 of the hanger bar or transversely extending member of'the hanger is curved on an arc to accommodate the curved wall ortion of the opening 27 being made of su stantially the same radius of curvature as said wall portion or of a slightly smaller radius of Said blocks are generally reccurvature so as to give a certain amount of freedom of movement between the brick and hanger bar. The stops or projections 20 are normally raised above the top of the wall of the opening with the inwardly offset faces 22 of the members 21 in engagement therewith. While the members 20 are rounded and of slightly-less radius than the openings 27, these may be of any desired configuration, it being only necessary that they be of such a shape and size that they will pass through the opening 27 when the opening in the block is aligned therewith.

As the upper portion of each brick or block is of less thickness than the lower portion thereof due to the inwardly offset portion 22, the arrangement of said bricks or blocks in pairs or the hanger member as shown in Fig. 4 will provide a space to accommodate the perforated ear 16 as well as to accommodate the end enlargements 20. Furthermore, means is provided by this arrangement of quickly dissipating heat which lowers the temperature of the hanger bar 17 and the portions of the bricks or blocks in contact therewith, thus increasing the life and stability of both. As the ferrous alloys are, particularly, much stronger when cold than when hot and have a tendenc when heated to combine chemically with re clay or go into a solid solution therewith producing a compound which is extremely weak and fragile, this is highly important, particularly as it is the custom to make the hangers of cast iron where in contact with fire clay. By providing for dissipation of the heat, the contacting parts will be kept at a low enough temperature that the initial strength of the construction will be maintained in service.

As substantially circular openings are provided in the bricks or blocks and as the same are not slotted or undercut and are free from re-entrant angles, there is no tendency for the same to warp during manufacture. Moreover, the bricks or blocks dry readily and evenly, free from shrinkage,

cracks and no internal strains are developed tween the arch from firing. In other words, the bricks or blocks shown are of such a shape that they lend themselves readily to manufacture from fire clay material.

By the arrangement shown, the bricks or blocks are slidable into position on the hanger bars, but are prevented from slidlng off the same by the stops or enlargements 20 thus forming a unit which can be put'in place and removed readily and which will maintain itself as a unit when in position. Moreover, the hanger bar is free to rotate relative to the bricks or blocks to any desired degree and accordingly there isino binding of the hanger bars in the bricks or blocks and there is also no tendency to locallze stresses in the bricks either due to the weight thereof on the hanger bar or due to expansion upon heating.

Preferably I provide a packing of asbestos, mineral Wool, or other non-combustible cushioning material, indicated by the numeral 28 in the drawings, between the units atthe edges of the arch and the side walls of the furnace. This will permit the bricks or blocks constituting the arch to expand and yet not at any time leave and furnace walls through which air can be drawn into the furnace.

Having thus described my invention what I desire to claim and secure by United States Letters Patent is:

1. In a structure of the class described, and in combination, rows of refractory blocks andsupporting means therefor, each row of blocks and its supporting means being made up of a number of independently removable units, each of the units including a hanger having a transversely extending part with enlargements at the ends thereof, and a plurality of blocks having reduced upper portions provided with transverse openings therein to engage over the transversely extending part of the hanger, said openings being of a sizeto permit said enlargements to pass therethrough, said enlargements serving to hold the blocks from accidental endwise movement off the hangers while permitting the ready removal of the A provi end portions of the blocks being an opening besame, and said enlargements lying within the boundaries of the vertical planesof the larger portions of said blocks when the units of the row are assembled together.

2. In a structure of the class described, and in combination, rows of refractory blocks and supporting means therefor, each row of blocks and its supporting means being made up of a number of independently removable units, each of the units including a hanger having a transversely extending part with end. portions projecting upwardly from the upper face thereo'f,and a plurality of blocks having reduced upper portions provided with transverse openings therein to engage over the transversely extending part of the hanger, said openings being of a size to permit said end portions to pass therethrough, said end portions serving to hold the blocks from accidental endwise movement off the hangers while permitting the ready removal of the same, and said end por-' tions lying within the boundaries of the vertical planes of the larger portions of said blocks when the units of the rows are assembled.

3. In a structure of the class described, and in combination, rows of refractory blocks and supporting means therefor, each row of blocks and its supporting means being made up of a number of independently removable units, each of said units including a hanger having a transversely extending part with end portions projecting upwardly from the upper face thereof, and a plurality of blocks, each of said blocks being recessed adjoinin one face thereof at-its upper part to e a reduced portion, the remaining art of said face and the opposite face of the blocks being plane, the upper reduced provided with transverse openings therein to engage over the transversely extending part of the hanger, said openings being of a size to permit said end portions of the hangers to pass therethrough, said end portions serving to hold the blocks from accidental endwise movement oflf the hangers while permitting the ready removal of the same, and said end portions of the hangers lying within the boundaries of the vertical planes of the larger portions of said blocks when the units of the row are assembled together.

4. In a structure of the class described, and in combination, rows of refractory blocks and supporting means therefor, each row of blocks and its supporting means bea ing made up of a number of independently per part to provide a reduced portion, the remaining part of said face being flat, and the opposite face of the block being plane, said blocks being provided with openings in the reduced portions thereof to engage over the transversely extending part of the anger, the openings being of a size to permit said enlargements to pass therethrough, the enlargements serving to hold the blocks from accidental endwise movement off the hangers-While permitting the ready removal of the same, the blocks being arranged in pairs with the plane faces thereof back to back, one pair of each of said blocks being mounted upon the hanger at either side of said central ear, said enlargements and said ears lying within the boundaries of the verlt)icall planes of the larger portions of said In Witness whereof, I hereunto subscribe 20 my name this 7th day of December, A. D. 1925.

LYLE STOCKTON ABBOTT. 

